Introducing the new Mariner 2 Walnut

28 March 2012

Thank you, Steven Sashen, founder of Invisible Shoes, for providing much-needed clarity on a topic that is as polarizing as health care legislation, or whether Mad Men is a better television show than Breaking Bad. Last week, New York Times health and fitness reporter Gretchen Reynolds wrote about a new barefoot vs. shod running study on the Times Well Blog. The title of her article: Making the Case for Running Shoes.

Times of India used this absurd photo with its barefoot-bashing article; nor will you be metabolically efficient running this way.

Any time, you mention these two words– “barefoot” and “running” in the same article, the knives come out, with the shoe set positioned on one side, the barefoot bunch on the other. It’s like Braveheart without Mel’s blue stripes. The study has made international news and clucking sounds from self-appointed Anti-Barefoot Told Ya So’s, including this one from the Times of India, whose headline reads, “Barefoot Running may be Less Efficient,” followed by this info-deck: “A new study has raised doubts over the minimalist running shoe movement, which may have prompted people to ditch their running shoes.” (Call me cynical, but I wonder how many people in India go barefoot or wear flat sandals and the number of podiatrists and sports injury clinics there.)

Here’s Steven’s take (it originally appeared on Invisible Shoes) on the headlines-grabbing study that involved only 12 runners. or less than .ooooo6 percent of the running population in the U.S, yet the “data” has been extrapolated and recklessly disseminated by the media so that it has now begun to mainstream-morph into incontrovertible evidence that barefoot is less efficient than running in shoes. But “facts” can be awfully deceiving. Ask any magician or politician or some German physicist named Werner Heisenberg. — Bill Katovsky

***

University of Colorado Barefoot Running Study Debunked

by Steven Sashen

The media is having an anti-barefoot running field day thanks to a study published by some people right up the street from me at the University of Colorado (BTW, I’ve been living in Boulder for 19 years and nobody has been able to explain why they call the university CU instead of UC.).

Each of the dozens of articles about the study has a distinct flavor of elementary school playground taunting, “Nah, nah, nah, nah, boo, boo… barefoot running isn’t good for you!”

It almost feels like the press is enjoying creating a backlash to all the “pro” barefoot articles of the last two years, even though in every barefoot article I’ve read the media insists on publishing “both sides of the story,” and includes some doctor who’s never run a meter in bare feet and wouldn’t know decent barefoot running form if it ran him over, claiming that running without shoes will hurt you, bring shame on your family, and accelerate the coming apocalypse.

So, let’s take a deep belly breath or two and have a chat about the study. In fact, let’s start by talking about studies, in general:

Designing a biomechanics study is not easy. Aside from deciding exactly what you want to explore and the best design of the study itself (how you can test it), finding enough of the right kind of participants is often tricky, if not impossible.

It’s even more difficult to design a study that isn’t artificial in some way. That is, it’s showing effects in a lab that may not be relevant in the real world.

And, even more, many studies, while interesting, may not be relevant to the broader population. (Whenever someone quotes a study, or even just the habits, of elite marathoners, I respond “Unless you’re 5’5″ and weigh 105 pounds and run at 13 miles per hour for two hours… who cares what those guys do?)

Finally, the way the media picks up a study — this one or any of the previous barefoot studies — often adds some spin that isn’t in the actual study.

All of the issues I just raised are relevant as we take a gander at the CU study. By the way, if you want to see a lively and cogent critical look at the study, you can’t go wrong with reading the comments on the New York Times article about it. Frankly, this post probably won’t be as lucid as some of the comments there.

Okay, let’s jump into it… The gist of the study:

“In the study, 12 subjects with substantial barefoot running experience ran at 7.5 MPH with a mid-foot strike pattern on a motorized treadmill, both barefoot and in lightweight cushioned shoes (~150 g/shoe, 5.4 oz). In additional trials, they attached small lead strips to each foot/shoe (~150, ~300, ~450 g). For each condition, they measured the subjects’ rates of oxygen consumption and carbon dioxide production as an index of metabolic cost.”

And the results:

a) For every 100g (3.5oz) (the average weight of a deck of playing cards) added per foot, energy cost increases by approximately 1% whether running barefoot or shod.

b) Running barefoot and in lightweight shoes do not significantly differ in energy cost.

Now, let the fun begin. Can you find the “confounds” (the factors in the study that might affect the results, or the interpretation of the results)?

I’ll start. Let me know if you find more.

1) How did they determine that the 12 subjects had “substantial barefoot experience?” Well, the study says, “8 km/week barefoot or in minimal running footwear (e.g. Vibram FiveFingers) for at least 3 months out of the last year.”

Does 3 months out of the last 12 really equal “substantial?” I’ve been barefoot for 3 years, and I’m STILL improving my form.

And if that three months was wearing VFFs or minimalist shoes, that counts as “barefoot experience” Uh…

Now the researchers did verify that the subjects all ran with a “midfoot or forefoot” landing. I know that Lee Saxby, the spokesman and coach from Vivobarefoot would have an issue with that. He doesn’t think midfoot is proper barefoot form (there’s some debate about that, but it’s besides the point at the moment).

2) They ran on a treadmill. Look, I get that testing runners on an actual track is hard and expensive, but running on a treadmill is not the same as running on the ground, end of story. It may give some useful data, but if it walks like a duck and quacks like a duck, but the duck is on a treadmill… hmmm, that analogy isn’t quite working, but you know what I mean.

I did some high-speed video analysis of my running at the Monfort Human Performance Lab. I hit 21 mph on that treadmill. I can tell you that when I’m on a treadmill, my stride is different than on the track. I overstride so I can “catch” the treadmill belt, for example.

3) To simulate a running shoe’s weight, the researchers put lead weights on the top surface of the runners’ feet. Do you think some small weights pressing down on your foot is different than having that same amount of weight distributed evenly, and mostly under your foot, thanks to the design of the shoe? I do. Does that matter? Could be. Is there a way to check… not easily.

4) The runners were at 7.5 miles per hour. That’s slow for an elite runner – about 200 meters in a minute, a quarter mile in 2 minutes, a mile in 8 minutes — but fast for most casual runners. This raises a few questions:

a) How was that pace compared to the runners’ usual training pace?
b) Does speed make a difference?
c) What about turnover, or cadence? Were those controlled and the same when the runners were barefoot vs. shod?

Got me. But, suffice it to say, we’re seeing the artificial quality of the study.

5) Oh, this wasn’t mentioned above, but I’ll give it to you now: the runners were wearing yoga socks. ““For the duration of the experiment, subjects wore very thin, slip-resistant yoga socks for safety and hygienic purposes.”

Hygienic purposes? Uh, some 409 and a paper towel would handle any “hygiene issues.” And “safety”? If you read the study, one aspect of “safety” is “avoiding blisters.”

Boy, where to start on that one? We know that socks does not equal barefoot, and we also know that if you get blisters when you run barefoot, you’re doing something wrong. So, this brings us back to number 1 — how experienced were these runners really?

6) The study measured oxygen consumption and carbon dioxide production. Okay, that’s a fine way to measure efficiency, based on the idea that using less oxygen and producing less CO2 means you’re using less effort, and that equals being more efficient.

But here’s a question: So what?

For one: does using less energy equate to faster times? It seems like it might, but that’s not a given.

Does the amount of extra energy being used by *some* of the barefoot runners have any relevance to the average runner? Someone for whom 7.5 mph is too fast… or even too slow?

7) Oh, here’s a favorite. The runners in the study wore an ultra-lighweight racing flat. Most runners wouldn’t wear those. And most runners with no barefoot experience wouldn’t find those any friendlier than being shoe-free.

Don’t get me wrong, I’m thrilled that my Boulder neighbors are researching barefoot running. And while this is the first published study, I know they have more coming and I’m looking forward to those.

And I’m certainly not blaming them for how the media is handling the story.

My only interest is the continued exploration, conversation, and understanding of efficient movement, running for speed and/or distance, and the ways of teaching and exploring barefoot running (and walking and hiking).

No one study can perfectly address all of the open questions. But the almost combative attitude where everyone wants to jump on some one-sided “We’re better!” bandwagon certainly doesn’t help.

Now, if you’ll pardon me, I have to burn off some of my frustration by putting on some yoga socks and minimalist shoes and going for a barefoot run.

Comments (21)

Why do you go to such great lengths to debunk research that is not supportive of the agenda that you are pursuing, but not hold up the research that allegedly supports your agenda to the same scrutiny? I smell a hypocrisy.

Michele,
Thank you for the reply. The beauty of Steve is he will tell you what he thinks. it is a blog and his commentary. I know Jason and the study is well done for what they were studying....metabolic cost of a very light shoe compared to toe socks and weights on the feet in a very small group of runners which may or may not have represented true habitual barefoot runners. They chose the best group they could find for the moment. I'm on year 2 barefoot and still improving and learning. The study was great and clearly struck the interest for larger studies. Thank you CU (or UC) team. i love good research and debate.
Here is my take:
Even as a a barefoot runner in a Western world, I run faster in shoes and when I race I wear shoes too. You can be a bit reckless and it is less work. You do not have to adapt to all the textures of the surface. I use a very light Newton MV2.
I think when all the needless shoe debates are over we will ultimately get at the real message of Born to Run and the Tarahumara. Running is play. Dr. Stuart Brown sums it up: “Play is purposeless and all consuming. And most important its fun.”
Play is disconnected from outcomes. You are in the moment. In a scientific data driven world, play resists all efforts to analyze it. We just posted a piece on this topic.
I tell runners to rediscover the exhuberance of being in the moment . To me an activity such as barefoot running, which is play, has a more important meaning to the individual runner that will never be studied.
If one wants to see what it does for them- go play a little in your barefeet and there does not need to be a result. You will learn something unique to you. You WILL improve your form and strength if you listen to your body. Speed or running economy? i do not know.
Interesting point on the metabolic cost too. i just did a VO2 max tast (barefoot on T-mill). My running economy was best at about 7 min a mile. Slower was less efficient and and as i got toward LT the costs rose again...so yes there is a "sweet spot" too.
All good debate....run with or without shoes. Just go run and play!
Mark

Hi Michele,
I've actually been as critical of the "pro-barefoot" studies as I am about this one.
To date, nobody has crafted a study where a large cohort of runners of varying skill levels are taught to run barefoot (or, for that matter, told to merely remove their shoes without any further instruction), and monitored over time (and compared with a control group of shod runners over that same period of time).
The reason?
For one, COST.
That's an expensive study to do.
Secondly, it could be so full of confounds that it would be difficult to extract useful data. (e.g. maybe there's a difference between overweight men under 45 years old who were high school athletes, and those who weren't high school athletes... that would be tricky to tease apart).
That said, I've been alerted to a study coming out next week that compared specific biometric measurements when runners were barefoot, in standard running shoes, and in Invisible Shoes. I'll confess that I probably won't spend a lot of time criticizing it (BTW, I had nothing to do with the study other than providing footwear). Then again, it's rude to criticize someone who pays you a compliment ;-)

Oh, I left something out of my original post...
What if the study is correct, though? What if barefoot running is less efficient than shod running?
The only answer I can come up with is: Who cares?
I don't mean that it's not important to know. I mean, literally, who should care?
If you never race, you'll never notice any difference in efficiency (assuming, again that "decreased efficiency" = slower times).
Besides, there are MANY other reasons to run with bare feet than the idea that it's more efficient... many that have barely been touched on (Dr. Michael Merzenich and I have had some interesting chats about how being barefoot could help the elderly in various ways).
Personally, I didn't make the switch for efficiency's sake. In fact, for me, as a sprinter, I know I'm more effective in spikes than barefoot.
I switched because it helped me correct some form problems, eliminated injuries I was getting, turned running from a chore into an enthralling discovery, and, more importantly... WAS FUN.

Roger that 100%....but i just ran a road mile race barefoot in 5:02 at McCormack Mile Charlottesville. That is good karma for when i put the shoes on....i'll fly! Steve need some of your speed coaching. i'm a slow twitcher. Dr. Mark

Anybody who has experienced walking/running barefoot or with barefoot/minimal shoes knows that the NY Times article on the research was *spin* at it's finest.
However, the overall findings on metabolic cost makes total sense, e.g., Additional load means more work or output.
I'm sure some would agree that it is common sense. But people get paid to do research, and that unfortunately can lead to scientific sensationalism/materialism.
Of course, the masses will probably come away with the notion that a running shoe is better than going barefoot.
That of course is not what the research and the people doing the research were trying to show.
I do find it a little odd that they make a point of mentioning a Nike running shoe which if I'm not mistaken, is their brand *new* technology.
Due to the amount of mechanoreceptors there is know way that running with anything covering the sole of the foot is better (or more efficient!).
In other words, faster does not mean more efficient.
The bare forefoot/midfoot will have a quicker reaction time to the ground, gravity and momentum guaranteed. That does not mean that we should ignore technique/skill/training or even a barefoot/minimal shoe.
Since the researchers applied the load to the top of the foot, the tibialis anterior and extensor hallucis longus would work much harder to decelerate the foot in a natural environment, e.g., The ground. Both muscles go to to the medial (inside) of the foot and therefore eccentrically lengthen to decelerate/control the foot as it comes into the ground.
Unfortunately, the research was done on a treadmill which should be acknowledged. Mainly, because any valid findings only apply to that environment.
The same muscles will work harder than normal at initial contact on a treadmill as well. This of course is due to the placement of the load relative to the axes, but to a lesser degree. The load on the top of the foot is the same, but due to the forward pull of the tread, the treadmill pulls the lower leg/hips over the foot which is not normal or natural in anyway.
The treadmill then, is an artificial environment and the muscles/fascia are not called upon in the same way.
Due to the nature of the load and the placement of the load...I'm sure the metabolic cost would be more with no shoes in both environments. However, it should be noted that the treadmill is assisting the neuromuscular (fascial) system in more ways than one on a treadmill.

As a doctor of muscle physiology/biomechanics, barefoot runner, and 50 year old somewhat "gravitationally challenged" male I find this article's conclusion great news. I greatly enjoy the feel of OEM (original equipment manufacturer) running and the new hobby of gait retraining, and now I know I burn more calories per mile to boot! Honestly, anybody that would care about metabolic efficiency and knew what they were actually seeking would have little trouble competing in flats on race day for that "extra edge". For 99.9% of us, less efficiency is a free bonus towards our weight control goals.

barefoot isn't just good for efficiency, it allows the body to, most importantly, DEVELOP THE WAY IT SHOULD
if you wear something, the less amount of material on the foot, the better
i also don't like laziness when it comes to exercise...wearing shoes that make you not do as nature intended, well, isn't good
of course, i can't go barefoot ALL the time...but at least i'm trying
and if i grew up with a lot less shoe like i did when i was 5 years old and younger...i wouldn't have this problem, and neither would everyone else
it all boils down to common sense, how have our bodies worked for the time we've been on this earth? only a little blip is with shoes

Why get so worked up about an 'efficiency' study. Who cares? Most people I talk to aren't going barefoot for efficiency. It's about fun, getting closer to nature, and returning to a human running style.

I just recently got back into running a couple years ago, and started by going out and buying the most expensive running shoes I could find. I went through several pairs of shoes, each with its own problems causing me to find another pair that may work. Every time I went to the running shoes store, I was guided to one pair or another to fix my problems, and each time I was assured that this current selection would indeed fix my pains. After finding a pair that felt right and did not give me blisters, I thought I was on the path to a lifetime of great running adventures. Well I was wrong. I fallowed what all the books told me, and built my endurance up through walking and running combinations. I was reaching previous records from my youth, and everything was great, until one day my knees failed me. I do not have insurance, so I never went to see a doctor. I let the injury heal, and over time I thought it went away. I started to walk again to build my legs back up, and when I thought I was ready I tried to run again, yet the pain was still there. To me it was hopeless. It was not until a friend introduced me to barefoot running and Vibram shoes that I regained hope. I started slowly, and worked my way back into running. It was a process, and one I have done before, but this time it was done without injury to my body. Just to prove to myself that it was not in fact just the shoes, I have tried to run in my old shoes, or other non-minimalist shoes, and have found myself walking back after a short run, due to the shooting pain in my knees. So, to me this study means nothing. I have been running painlessly in Vibrams for two years now, and hope to continue for as long as I am here on this planet.

I *just* realized that the conclusion of the study was WAY off base!
Here's why:
The researchers think that the efficiency of the shoes came from the PADDING absorbing some of the stress that the muscles have to handle when you're barefoot.
In other words, the ENTIRE efficiency effect could be ALL about the padding and not at all about the weight. The weight issue would only be valid if they tested multiple shoes of the same weight with different types of outsoles and got the same results.

They tested on a treadmill??
The results are totally useless then. Its totally different to real running.
Running bareroot/minimalist since half a year: knee and hip pains are totally gone. Much better training for all leg muscles. And running is finally fun again, because its so effortless and without pain.

So the author is anit-shoe?
or Pro-shoe?
NOT clear.
Bottom line: barefoot is not the same as shoes. right?
So Barefoot shoes are shoes.
Barefoot means you run withOUT shoes on.
And running shoes are the best way to run.
Right?